The present invention relates to a push-button switch. More particularly, it relates to a push-button switch of momentary operation which has a light touch for actuation and requires reduced space.
As momentary switches, various structures have heretofore been proposed and put into practical use. A well-known momentary switch is as shown in FIG. 1. A movable contact piece 11 is constructed by forming a highly-resilient electrically-conductive metal sheet into the shape of a bowl. A contact portion 11a of the movable contact piece 11 and respective contact portions 12a and 13a of stationary contact pieces 12 and 13 are arranged in a case 14 in a manner opposed to each other. By depressing a push button 15, the movable contact piece 11 is inverted to bring the contact portion 11a of the movable contact piece 11 and the stationary contact portions 12a and 13a into touch with each other. Thus, a switching circuit is turned "on". Upon releasing the depression of the push button 15, the spring force of the movable contact piece 11 acts to return the push button 15 and the contact portion 11a to their initial positions. Then, the switching circuit is turned "off".
Such prior-art momentary switches have the structure in which substantially the central part of the movable contact piece 11 is depressed in the height direction thereof. Therefore, the space required for the switch is liable to become large, which forms an obstacle to the miniaturization of equipment containing the switch. This disadvantage appears more conspicuously as the number of switches to be used increases.
The structure of the prior-art momentary switch in which the movable contact piece is depressed in the height direction thereof is also disadvantageous in that the inverting operation of the movable contact piece is not transmitted to the finger, so the feel of change-over is feeble.